Oil burner



5 Aug. 15, 1 944.

F. w. BENTLEY OIL BURNER Filed Dec. 6, 1941 l 3 Sheets-Sheet 1 11:: .ZIIIIZI'IL INVENTOR M m 5 I Y M H F W. BENTLEY O-IL BURNER ,Filed Dec. 6, 1 941 Aug. 15, 1944.

3 Sheets-Sheet 2 INVENTOR /7ayc/ W fienf/ F. W. BENTLEY Fild Dec. 6, 1941 Aug. 15, I944."

Ala m Patented Aug. 15, 1944 UNITED STAT u on. BURNER.

' Fl'oy'd W. lfentley, Brooklyn, N. Y.

6, 1941, .Serial'No. 421,896-

1 Application December This invention relates to oil burners and has for an object the provision of improvements in this art. I

As greater efliciency is demandedin oil-burner installations, the demand being most insistent in the industrial field, it becomes increasingly desirable to use highly superheated air for atomizing and burning the fuel. If air temperatures up to 650 F. could be used, the combustion efficiency would be greatly improved over present practices; It is, indeed, possible to-employ such highly heated air in burners of the gun type, but it"is desired to use it 'in the much more-efficient rotarytype burner; and here the necessary proximity of the rotor drive motor to the burner and hot air manifold has caused such overheatingof the motor and its bearings as to make its use impractical. It has been proposed that liquid cooled bearings be used, but this has proved equally unsatisfactory. u

According to the present invention, the use of a motor close to the hot air manifold is made feasible by improved assembly and cooling means which provide for the maintenance of a lowopcrating temperature for the motor and the rotor shaft bearings.

The objects, advantages and novel features :of the invention :will be made manifest by the ifollowing description of .an illustrative embodiment of theinvention, reference being made to the accompanying drawings wherein:

' Fig. 1 is afront elevation of an oil burner installation embodying the presentinvention; .Fig. 2 is a correspondingplan view; and Fig.3 is a vertical section taken onthe line. of Figs. 1and,2.. 1 I I I Referring to the drawings, the numeral II] denotes a refractory lined combustion chamber. or firebox of a furnace. A burner II and a plurality of ducts I2 for a supply of secondaryair provide the source of heat for the firebox. The manifold I3 for the secondary air around the firebox is not completely shown but this is a common arrangement and concerns thepresent invention only as a region of high temperature adjacent the oil burner motor I4 and the bearings I5 of thetubular shaft I6 of the burner spinner cup H. A manifold I8 for primarycombustion air at high temperature (say upto 650 F. or above) constitutes an even closer region of heat which is normally injurious to the motor and its bearings. A temperature above 300 F. atthe motor or spinner shaft bearings is not permissible. Preferably a much lower temperature is maintained.

on injected into the Spmner tung through a nozzle 20 on the end of a fixed oil supply tube 2| mounted coaxially within the spinner shaft IS. The tube '2I is mounted on a support 22 secured to the motor casing.

The air from the primary air manifold I8 enters the firebox around the spinner cup I1 by way of a coaxial duct 25 and serves to break up the oil which is thrown off as a cone-rshaped sheet from the end edge of the spinner. The circumferential inclination of Vanes 26 within the tapered end of the air duct 25 has an effect upon the spread or conical pitch of the resulting flame from the burner.

Heated air for the primary air manifold may be derived from a blower 21, and if desired this same blower may supply air to the ducts I2 of the secondary air manifold I3.

The burner, II, motor I4, manifold I8 and closely related parts are mounted on a closure plate 30 carried on a hinge 3|. The oil line 32 to oil tube 2I is jointed on the hinge line, and the manifold I3 is connected .to a fixed air conduit 33 when the plate 30 is in closed or operative position. The plate 3.0 may be retained in closed position by securing devices 34. Theconduit 33 may be provided with a fiow controlling damper 35., The novel means which make practical .the useof a spinner motor and bearingssoclose to the region of high temperatures in the preheated air manifolds comprise devices for creating a separating wall of cool air between the motor and bearings and the hot zone. It is to be noted that there are no bearings for the spinner shaft I6 within the hot zone of the manifold I8, hence the bearings I5 which support the shaft must be located as near as possible to the manifold:

The means herein illustrated formaintainin this separating wall of cool air comprise a conical shield 40 of such size as to completely screen the motor from the proximate hot zones. The

shield is shown to be secured to the manifold I8,

asby bolts 4I heat insulation 42. being provided, if desired, to minimize heat conduction between the connected parts. Spatial separation instead of, orin addition to, the heat insulation may be employed and heat conduction may be further minimized by securing the shield to the motor casingor to the motor support 43 instead of to the Th shield 40 may be ofgood heat conducting material, such as metal, and is provided with generally radial cooling vanes 44 on one or both sides, here shown on the inner side. I

A secondary shield is provided by a plate 45 which is secured: within the conical shield, :as

welded fingers, 49v at circumferentially spaced.

points around the conical shield provide convenient means of attachment of the parts by the bolts 46.

A forced circulation of air between the shields 40 and 45 maybe created by a fan 5| secured to the shaft I6 within the enclosed space. A set screw 52 may be employed for securing the fan to the shaft. curved and aligned with the shaft axis or inclined to the axis to draw air back forcibly against the shield 40, as shown.

By the provision of a removable cover plate 54 of sufficient size on the manifold IS, the entire motor and spinner cup assembly may be readily removed from the door assembly carried on the plate 3!]. Bolts 55 provide a convenient means of connecting the parts.

The double spaced shields-and forced air circulation therebetween provide adequate protection for the motor and bearings even when placed very close to the hot air manifolds. The air circulates in an effective manner, the cool air being drawn in over that part of the motor nearest the shields and passing out in a wall or sheet between the shields. It is found that this apparatus is very effective, keepin the motor andbearing temperatures down to about 100 F. above prevailing room temperatures. Thus, if roo'mtemperature is 70 F., the motor temperature can be kept as low as 170 R, which is well within the limit of 300 F. which must be maintained to preserve the motor and bearings. The apparatus provided'is simple and effective and may be readily installed on existing equipment where it is desired to raise the temperature of thecombustion air supply for greater efliciency."""-

While one embodiment of the invention has been specifically described to illustrate the principles'of the invention, it is to be understood that the invention may have various embodiments within the scope of the following claims."

I claim: a 1;'In an oil burner installation inwhich the air for combustion is highly preheated before introduction into the combustion chamber, and

in which the driving motor and all of the bear ings for the burner rotating shaft are located outside the combustion chamber and outside, but closely adjacent, the preheating'manifold, means for cooling said bearings to a relatively 'low tem perature, comprising, a shield between said mani= fold and said motor and bearings;-and suction means mounted between said shield and said motor and partially enclosed in" a chamber of which said shield forms one wall, for drawing cool air'past the adjacent end of the motor and the adjacent set offlbearings into said partially "en closed chamber to impinge against-said shield,

and thence to escape from said chamber;

I 2. In an oil burner installation in whichthe air for combustion" is highly preheatedjbefore introduction into the combustion chembenand in which the driving motor and all 'of the bearings for the burner rotating shaft are, located closely adjacent, the preheating manifold, means for cooling said bearings to a relatively low temperature, comprising, a conical, outwardly flared shield between said manifold and said motor and bearings, and suction means mounted between said shield and said motor and partially enclosed in a chamber of which said shield forms one wall, for drawing cool air past the adjacent end of the motor and the adjacent set of bearings into said partially enclosed chamber to impinge against said shield and thence to escape from said chamber.

3. In an "oil burner installation in which the air for combustion is highly preheated before introduction into the combustion chamber, and

v in which the driving motor and all of the bear- The fan blades may be flat or outside the combustion chamber and outside. but id ings for the burner rotating shaft are located outside the combustion chamber and outside, but closely adjacent, the preheating manifold, means for cooling said bearings to a relatively low temperature, comprising, a conical, outwardly flared, radially vaned shield between said manifold and said motor and bearings, and suction -means mounted between said shield and said motor and partially enclosed in a chamber of which said shield forms one-wall, for drawing cool air past the adjacent end of the motor and theadjacent set of bearings into said partially enclosed space to impinge against said shield and thence to escape from said chamber.

4. In an oil burner installation in which the air for combustion is highly preheated before introduction into'the combustion chamber, and in which th driving motor and all of the bearings for the, burner rotating shaft are located outside the combustionchamber and outside, but closely adjacent, the preheating manifold,-means for cooling said bearings to a relatively low temperature, comprising, a conical, outwardly flared shield and a base plate shield clamped thereto at points but spaced-therefrom except at said points, both shields being disposed between said manifold and said motor and bearings, said base plate shield-being open at the center, anda fan on the shaft betweensaid shields for drawing cool air past the adjacent end of the'moto-r and the adjacent set of bearings through said central opening to impinge upon said outwardly flared shield and forcin it out between said shields;

' 5.- In an oil burner installation in which the air for combustion is highly preheated before introduction into the; combustion chamber, and in which the driving motor'and all of the bearings forzthe burner rotating shaft are located outside the combustion chamberand outside, but closely adjacent, the preheating manifold,.means for cooling said bearings toa relatively lowiter'nperature, comprising, a conical, outwardly: flared shield and a base plate shield clamped thereto at points but spaced therefrom .except at such points, both shields being disposed between said manifold and said motor and bearings, said base plate shield being open at the center, and a fan on the shaft between said shieldsfor drawing cool air past the adjacent end of the motor and the adjacent set of bearings through. saidcentral opening to'impinge upon'said outwardly flared shield and forcing it out between said shields, said conical shield being provided with interior radial vanes.

6. In an oil'burner installation in which the 'airfor combustion is highly preheated' be'for'e' outside the combustion chamber and outside, but closely adjacent, the preheating manifold, means for cooling said bearings to a relatively low temperature, comprising, an outwardly flared shield and a substantially fiat base plate shield spaced therefrom but removably secured thereto, both shields being mounted axially on a common shaft and between said manifold and said motor and bearings, the shield disposed on the motor side being open adjacent the shaft, and a fan mounted on said shaft between the shields and adjacent the opening for drawing cool air in between the shields past the adjacent portion of the motor and the adjacent bearings to cool the same, said air thereafter flowing out at the periphery of said base plate shield.

FLOYD W. BENTLEY. 

